A technique to acquire position information for a user by using various sensors that are mounted on a portable terminal device such as a smart phone has been developed in recent years. Various services using a user's position information has been started as well.
For example, when the current position of a portable terminal device is measured by using a position information acquiring unit such as global positioning system (GPS) module that is mounted on the portable terminal device and the portable terminal device approaches an area (a shop, a station, or the like) designated by a service provider, there is a service that distributes recommendation information, such as an application and coupons that may be used in the area, to the portable terminal device from a central server.
In a service such as described above, the portable terminal device executes an installed application so as to regularly acquire the current position of the portable terminal device from GPS or the like and transmits position information for the acquired current position to the central server. The central server determines whether the user is in a service area based on the position information received from the portable terminal device, and distributes recommendation information such as an application and a coupon to the portable terminal device of the user when the user is in the service area.
In the above-described configuration, because the server determines whether the user is in the service area, an application installed in the portable terminal device does not know which area a service that is registered in the portable terminal device belongs to. Therefore, the portable terminal device regularly transmits position information for the portable terminal device to the central server, based on the installed application.
As the period between transmissions is increased, power consumption may be reduced. However, the greater the period of transmission from the portable terminal device, the greater the chance that, during the time between transmissions, the portable terminal device will completely pass by a position where a service is provided. Therefore, it is preferable that the portable terminal device continue to transmit a user's position information to the central server with a short cycle so that the user is provided with an optimal service corresponding to the current position of the portable terminal device.
Japanese Laid-open Patent Publication No. 2009-198458 and Japanese Laid-open Patent Publication No. 2011-27500 are examples of related art.